Color image formation in silver halide photographic light-sensitive materials can be achieved by exposure to light and color development, upon which an oxidation product of an aromatic primary amine developing agent is reacted with a dye forming coupler. In this image formation system, color reproduction is generally realized by a subtractive color process, in which blue, green and red colors are reproduced by forming yellow, magenta and cyan dye images that are complementary to the former, respectively. The cyan dye forming couplers most often employed are phenol dyes and naphthol dyes.
Dye images obtained from conventionally employed phenol dyes or naphthol dyes have several problems, however, in terms of preservability. For example, dye images obtained from 2-acylaminophenol cyan couplers disclosed in U.S. Pat. Nos. 2,367,531 and 2,423,730 are, in general, inferior in heat fastness; dye images formed from 2,5-diacylaminophenol cyan couplers disclosed in U.S. Pat. Nos. 2,369,929 and 2,772,162 generally have poor light fastness; and those obtained from 1-hydroxy-2-naphthamide cyan couplers are unsatisfactory in both light- and heat-fastness.
On the other hand, it is known that when a polymeric coupler prepared by polymerization of a monomer coupler is added to a hydrophilic colloid composition in the form of a latex, not only is the film prepared therefrom free from deterioration in strength, but also a coupler unit can easily be incorporated in an emulsion at a high concentration since the latex can contain the coupler unit at a high concentration. In addition, such a composition can be formed in a thin film because of suppression of viscosity, so that the resulting materials exhibit improved image sharpness.
Examples of such polymer coupler latexes incorporated in gelatin silver halide emulsions include 4-equivalent magenta polymer coupler latexes and processes for the production thereof as described in U.S. Pat. Nos. 4,080,211 and 3,451,820 and British Pat. No. 1,247,688, latexes of copolymers with competing couplers as described in West German Pat. No. 2,725,591 and U.S. Pat. No. 3,926,436, and cyan polymer coupler latexes synthesized by the emulsion-dispersion method as described in Research Disclosure RD No. 21728, pp 188-190 (May, 1982).
However, these known cyan polymer coupler latexes are still somewhat unsatisfactory despite the above-described advantages, and improvement in heat- and light-fastness and sharpness of dye images has been desired.
Further, conventionally employed phenol and naphthol cyan couplers have been noted to have drawbacks such as that the dye images formed therefrom by color development have poor fastness to heat or light and that reduction of color density takes place when development processing is carried out using a bleaching solution with weak oxidative activity or a fatigued bleaching solution. In order to overcome these disadvantages, phenol type cyan couplers having a phenylureido group at the 2-position and a carbonamido group at the 5-position have been proposed, as disclosed, e.g., in Japanese Patent Application (OPI) Nos. 65134/81, 204543/82, 204544/82, 204545/82, 33249/83 and 33250/83 (the term "OPI" as used herein refers to a "published unexamined Japanese patent application"), etc. It is certain that the 2-phenylureido-substituted couplers are superior to the known phenol cyan couplers or naphthol cyan couplers with respect to the above-mentioned points. Nevertheless, these cyan couplers still involve a disadvantage in that spectral absorption of a developed color image widely varies from shorter wavelength absorption to longer wavelength absorption, depending on the color density.